"The lunatics had taken over the asylum," says James Lavelle of the music industry of the mid-90s. "There was a shitload of money going around, it was fuckin' New Labour, anything was possible, we were very young, everybody was coming together, everybody was hanging out, all these people coming through at the same time. It was this hugely fuelled thing – not just about drugs, or clubs, or the dark side of it – just excessive. Virgin Records had just had the Spice Girls and sold 30m records; they had 200m quid in the bank, so [for them] it was like: 'Let's spend money on Massive Attack and have ridiculous videos!'"

Right in the heart of all this, somewhere between the cash-drunk mainstream and the dark fringes, was Mo' Wax, the label Lavelle ran from 1992 to 2002. With its roots in hip-hop and jazz-funk, Mo' Wax became the driving engine of a new genre, trip-hop (a term it used on early sleeves) – in the process making superstars of acts from DJ Shadow to Dr Octagon and DJ Krush.

Now a vast archive of Mo' Wax-related material – locked away when Lavelle terminated the label, and unseen even by him for a decade – is being released, for a planned book and art exhibition to mark the label's 21st anniversary. There's a Kickstarter campaign to fund it all, and Lavelle is organising a special-edition reissue of Psyence Fiction, the sprawling 1998 album he made with DJ Shadow under the moniker UNKLE, featuring the unlikely supporting cast of Thom Yorke, Ian Brown, Richard Ashcroft, the then virtually unknown Badly Drawn Boy, Kool G Rap, Mike D of the Beastie Boys and Talk Talk's Mark Hollis.

Though he has clearly calmed down since the days when he was known as one of the more bumptious hustlers of 90s music, Lavelle is still not troubled by modesty about the label. One moment he says he won't compare it to "Led Zeppelin or the Beatles or Oasis, or even a label like Def Jam", then promptly does pretty much exactly that. "When it's really good, when you've been a part of the culture, the amount that it's possible to achieve in that first eight-to-10-year period is mindblowing," he says.

The precocious son of a well-to-do Oxford family, Lavelle started DJing at 15, relocated to London within a year, founded Mo' Wax at 18 and promptly blasted open a niche for himself in the music industry. He not only acted as the lynchpin of trip-hop, but was able to mingle all strata of British music, from the most staunchly underground of jungle and electronica heads to the leading lights of superclub rave and Britpop. The label itself appealed to everyone from Face-reading, sneaker-obsessed proto-Nathan Barleys to shaven-headed techno fanatics; and the 1996 release of Endtroducing..... made DJ Shadow a mainstream name. More than just a label, though, Mo' Wax was also a repository for graffiti art, new design, hip-hop culture and more.

Retrieving this archival material from a west London lock-up has clearly been an emotional process for Lavelle. More than anyone since perhaps Creation's Alan McGee, he was the figurehead of his own label for its entire existence. When he opened the doors, he says, "literally everything from a 20-year period of my life was in there. Going through stuff, it'd be your first DJ flyers, to business letters, to notes from relationships. It's my world, just there, amassed together, in these boxes." It's significant, too, as a symbol of the pre-internet age: all those personal notes, sketches and drafts nowadays would be lost in the "cloud". And of course it's a unique art collection.

The poet and DJ Charlie Dark, who recorded for the label as Attica Blues, says Mo' Wax "pulled together music, art and street culture from around the world and spat it out in a format that the new generation could understand and, more importantly, afford". Visual artists, most notably the New York graffiti veteran Futura2000 – but also the likes of 3D from Massive Attack – were key figures in the label's history, and Lavelle collaborated with creative fellow-travellers such as the Japanese fashion label A Bathing Ape.

The label's record sleeves alone number as many as 500; promos and limited editions were all given different artwork. Add to that toys, promotional gizmos and other merchandise, plus "every prototype, every proof of every cover, all the original artwork, mixtapes, things that were never released, DAT tapes, cassettes" – all of it hoarded with the same obsessive-collector's mentality that led him to DJing in the first place, and you end up with a serious collection of the 90s pop culture that Mo' Wax lay at the heart of.

Although he insists the label was "seen as being pretty underground", Lavelle's partner at the time – and the mother of his daughter – worked with Alexander McQueen, and socially Lavelle was able to comfortably embrace the worlds of fashion (high and street), Britpop and dance culture. He found himself in the thick of a world of partying and Kate Moss-centric celebrity, and enjoyed it immensely – something that saw him skirting infamy in gossip columns, and caused mutterings of discontent among those who really did see themselves as underground.

But as he reels off lists of record stores, boutiques and clubs where "creative people met face-to-face" – Bluebird, Mr Bongo, Zoom, Four Star General, The Blue Note – it's hard not to share Lavelle's enthusiasm for this thronging pre-internet era. "What defined the times for me is how amazingly eclectic it was," he says. "It was the production era, it was records like Mezzanine, Dummy, Chemical Brothers, Underworld, Björk, Goldie – all these influences coming into records, to make completely new, non-retrospective music."

Mo' Wax reflected that eclecticism. The keystone Detroit techno producer Carl Craig, who released some of his more exploratory music for Mo' Wax with the Innerzone Orchestra and Urban Tribe projects in the late 90s, says: "They were adventurous. There were no boundaries, they weren't tied to any tempo, it wasn't like when all drum'n'bass had to have the same drum break, and it didn't have to sound like a DJ Shadow record – because they already had DJ Shadow!" Indeed, Mo' Wax released everything from ambient techno (Andrea Parker, As One), to psychedelic rock (South), to re-releasing the New York disco/postpunk band Liquid Liquid several years before their influence on the likes of LCD Soundsystem made them ultra-hip.

The end, when it came, was inevitably a comedown. "Things get engulfed," Lavelle says, "between ego, money, drugs, relationships, everything that goes on … It was a lot to carry on your shoulders at 27, 28, when you'd been doing it for 10 years, and also touring and DJing. Because I couldn't just A&R and run a record label – that's just not what you did. And I had a three-year-old daughter. And yeah, I burned out." After a brief partnership with XL Recordings fizzled out, Lavelle says he was offered another album deal for UNKLE. Then, with his career as a techno and house DJ taking off thanks to a residency at Fabric in London, he pulled back from "all the responsibility" of running Mo'Wax for the relative isolation of the recording studio and DJ booth.

"To my credit," he says of the way he left matters, "I hired Nick Huggett, who then signed Adele, and MIA and Dizzee Rascal [to XL]; I gave him his first job. So maybe in a weird way, if I'd have survived, who knows what records would've come out?"

Opening the archive is reopening not only the old wounds but the old inspirations. He has to visibly control his excitement when asked if he feels like "putting the band back together again" and making Mo' Wax active. "We'll see. What I'm going to do now is do this book, put together some exhibitions, clothes, re-release Psyence Fiction, do some kind of best of Mo' Wax in one form or another, collaborate with a lot of different artists, toy or clothing people, all the people I've worked with over the years to create something for next year, maybe add some new context to it …"

Older Lavelle might be less bumptious, but it's clear the appetite for the hustle is as strong as ever.